The overall goal of this project is to use in vivo NMR spectroscopy and micro-electrode measurements to provide detailed knowledge of the dynamic response of transplanted adenocarcinoma in C3H/HeJ mice to phototherapy using chemiluminescence photoactivation of hematoporphyrin derivative, (Photofrin II). This information, together with results of related independent studies of photo-therapy using external photoactivation, will be used to elucidate the mechanism of action for hematoporphyrin - chemiluminescence phototherapy. This project had the following specific aims: 1) determine the temporal relationship between the changes in tumor blood flow, P-31 NMR metabolic characteristics, and intralesional p02 and pH which are induced by hematoporphyrin-chemiluminescence phototherapy; 2) compare the effects of phototherapy using chemiluminescence photoactivation with the effects of phototherapy using external photoactivation, as determined in related independent studies; 3) evaluate the effect of tumor size on both the physiological response and the therapeutic response of tumors treated with phototherapy using either chemiluminescence or external photoactivation; and 4) examine the relationship between therapeutic response to phototherapy and the tumor NMR metabolic characteristics before and after phototherapy as a function of the dose of both chemiluminescence and external light photoactivation. In vivo P-31 surface coil NMR spectroscopy will be used to study tumor metabolic characteristics in response to activation by hematoporphyrin chemiluminescence. F-19 NMR in conjunction with fluorinated vascular markers (e.g., perfluorocarbon blood substitutes) will be used to provide a measure of relative rates of blood flow in treated tumors. Microelectrode measurements will be carried out to evaluate the distribution of the P02 and pH within the tumor. The combination to these techniques will allow us to assess the temporal relationship of P-31 metabolic characteristics, blood flow, and intralesional pH and p02.